Fungicidal and bactericidal 2-(n-2-cyanoethyldithiocarbamylmethylene-5-hydroxy-4h-pyran-4-one and metal chelates

ABSTRACT

2-(N-2-Cyanoethyldithiocarbamylmethylene)-5-hydroxy-4H-pyran-4one and metal chelates thereof are effective agents for controlling undesirable fungi and bacteria.

United States Patent [191 [111 3,852,444 DAmieo Dec. 3, 1974 FUNGICIDAL AND BACTERICIDAL [58] Field of Search 260/345.9; 424/283, 245

2-(N-2- CYANOETHYLDITHIOCARBAMYLMETHY- [56] References Cited LENE-S-HYDROXY-4H-PYRAN-4-ONE AND UNITED STATES PATENTS METAL CHELATES 3,284,287 1 H1966 DAmico 424/300 Inventor: John Joseph DAmico, Akron, Ohio Assignee: Monsanto Company, St. Louis, Mo. Filed: Dec. 3, 1973 Appl. No.: 421,312

Related US. Application Data Division of Ser. No. 228,368, Feb. 22, 1973, Pat. No. 3,799,945.

U.S. Cl. 425/245, 424/283 lnt. Cl A01ln 9/00 Primary ExaminerAlbert J. Myers Assistant ExaminerDouglas W.. Robinson Attorney, Agent, or FirmJohn L. Young are effective agents for controlling undesirable fungi and bacteria.

Ill Claims, No Drawings l 2 FUNGiCIDAL AND BACTERICIDAL free, the toxicant keeps the area sterile by inhibiting 2 2 C AN()- growth of any pathogen which may invade the area. ETHYLDITHIOCARBAMYLMETHYLENE). The term habitat is used in its ordinary dictionary sense ""5 AND E: meaning the place where the pathogen normally lives EL 5 and grows. Typical habitats are warm, damp places, for

example, locker-room floors or in the case of plant This is a division, of application Ser. No. 228,368, pathogens the habitat is the foliage of the plantfiled Feb 22 1973 now Us Pat 3,799,945 Fungicidal compositions are prepared by combining This invention relates to cyanoethyldithiocarbamic of above described toxjcants h a liquid or acid derivatives of kojic acid which are toxic toward l solld Gamer The chelates are Insoluble m water and microorganisms and are particularly valuable for con- Organic Solvents and the trolling Venturia inaequalis, the pathogen responsible cyanoethyldithiocarbamyldithiomethylene)-- f apple Scab diseasechlomalkenyl esters of hydroxy-4H-pyran-4-one is insoluble in water but is solcyanoethyldithiocarbamic acid have been described by uble in Certain Organic Solvents, fhr example, acetone DAmico as useful agents for the control of fungi, US. and dimethyl fol'mamide- Aqeuous dispersions of the p N 3 234 2 1 Applicant herein combines the toxicants may be prepared to form concentrates which cyanoethyldithiocarbamyl moiety with the kojic acid may be diluted with Water to form a p y Suitable for moiety to form new compounds which exhibit excellent application to the area to he pmtected- It is recomf i id l i i mended that a dispersing agent be used to facilitate the formation of a more stable emulsion. The toxicants SUMMARY OF THE INVENTION may also be blended with an inert solid diluent such as 2 (N 2 Cyanoethy1dithiocal-bamylmethylene) 5 talc, diatomaceous earth, fuller's earth, etc., to form hydroxy-4H-pyran-4one and its metal chelates are poy Compositions which are dispersed in an aqueous tent agents for the control of fungi and bacteria. The medium to form a h p In f y f the new toxicants are valuable for controlling organisms on Conventional formulahoh and aplphcatlon technlq'les living plants because they exhibit fungicidal and bacterare PP Q f the Subject toxicant and includes icidal properties at low concentrations but are devoid hombmahhhs Wlth h y know} Weftmg agents and of phytotoxic properties even at higher concentrations inert carriers and includes combinations with other functional biological agents such as herbicides and in- The subject compound is prepared by reaction of the Sechcldesammonium salt of Z-cyanoethyldithiocarbamic acid The CQhCehratiOH of toxicahthsed-varles depehdihg and 2 (ch|0romethy|) 5 hydroxy 4H pyran 4 one The upon the particular pathogen wh1ch the treatment IS inchemical formula for the compound is tended to control. Amounts of one percent to one part I a t per million are effective with dosages of about 100 ppm being generally used. Of course, it is understood that greater or lesser amounts may be used and that the in- OH vention applies to any concentration at which toxic ef- NCCFHCHINHQSECHPLO l fects or inhibition of the bacteria or fungi is obtained.

40. The metal chelates are prepared by complexing a I 2 %8g I L% metal salt with the 2-(N-2- cyanoethyldithiocarbamylmethylene) 5-hydroxy-4H- Example 1 pyran-4-one. Examples of suitable metals from which To a solution f 21 (Q 3 mole) f 2- Fhelales y h P p F h1 manganese cyanoethylamine and 18.9g (0.3 mole) of concentrated cobalt hlckeli pp Zmcr cadmlum lead and ammonium hydroxide in 300 ml of ethanol, there is mercury with the metals of atomic numbers of 26-30 added dropwise at 5a o c 223 03 mole) f b being preferred. The chelates are recovered as hydrates disu|fide Aft Stirring the mixture f 1 h at with the following postulated structure 25 3Q j 482 qj l f chlmpmethyl kojic acid in which M is a metal ion and x is variable but generally is added in one portion. Upon the addition, the temperis between 2-6 with x being about four when the cheature rises to 58C and precipitate forms. After stirring lates are dried at 45C overnight. the mixture at room temperature for 24 hours, 750 ml The new toxicants are effective bactericides and funof water is added and the mixture stirred for an addigicides and may be applied to the habitat of the pathotional half hour. The precipitate is recovered by filtragen to prevent its growth and spread. The bactericidal tion, washed with water until neutral to litmus and air or fungicidal compositions containing the toxicant are ,5 dried at applied to the area to be protected. If the area is al- Cyanoethyldithiocarbamylmethylene)-5-hydroxy-4H- ready infected, the toxicant kills or inhibits further pyran-4-one is recovered in 89 percent yield. The prodgrowth of the pathogen. If the treated area is pathogenuct recrystallized from acetone melts at ll66C.

Analysis gives 10.42 sa es; lG ahtl 2-4Tl 9 percent compared to 10.36 percent N and 23.72 percent S calculated for c,.,i-r,.,1 1 o s,.

Example 2 The Zinc chelate is prepared by adding at room temperature 4.5g (0.031 mole) of zinc chloride in 200 ml of water to a solution containing 16g (0.0619 mole) of 2-( N-2-cyanoethyldithiocarbamylmethylene )-5 hydroxy-4H-pyran-4-one and 10.9g (0.0619 mole) of percent sodium hydroxide in 400 ml of water. After stirring two hours, the precipitate is recovered by filtration, washed with water until neutral and air dried at 45C. The zinc chelate of 2-(N-2- cyanoethyldithiocarbamylmethylene)-5-hydroxy-4H- pyran-4-one is recovered in 100 percent yield (18 g). Analysis gives low values for nitrogen probably because of interference of the metal ion and 19.56 percent S compared to 18.85 percent S calculated for C H N O S Zn 4(H O).

Example 3 In one embodiment of the invention 2-(N-2- cyanoethyldithiocarbamylmethylene)-5-hydroxy-4H- pyran-4-one is applied to foliage of apple seedlings. Plants are selected for uniformity, sprayed with the toxicant and placed on carts to dry. Twenty-four hours later a spore suspension of Venturia inaequalis conidia is made and adjusted to a concentration of approximately 2,500,000 spores per ml. of water. The spore suspension is sprayed uniformly over the foliage of the treated and untreated trees. Immediately thereafter the plants are placed into the incubation chamber (100 percent relative humidity). Seventy-two hours later the trees are removed and after a drying period are placed on greenhouse benches. Two weeks later apple scab tests are evaluated. The test consists of counting the number of parasitized leaves on each plant (3 replicates per treatment), determining the average number of parasitized leaves per tree for a given treatment, and expressing the result as percent control. The percent control for each treatment is found by dividing the average number of parasitized leaves per tree in the untreated specimens into the average number of parasitized leaves per tree in the treated specimens, multiplying this number by 100 and subtracting it from 100. Comparisons are made with the commercial fungicide N-trichloromethylthio tetrahydrophthalimide (Captan). The percent control based on untreated trees (average of three) at various concentrations is shown in the following table.

Percent Control of Apple Scab Captan and 18.15 percent S compared to 17.63 percent S cal- Culated for C20H gN O S4Cd To illustrate control of bacteria and fungi, a 1.0 percent stock solution or emulsion of the test material is prepared in a non-toxic solvent and diluted in agar to provide samples containing various concentrations of the test material. Petri dishes are respectively filled with the test mixture and the plates thus prepared inoculated with the test organism. After a suitable incubation period, the plates are inspected and the concentration is recorded at which complete inhibition of the growth of the organism is obtained. Identical agar test plates with no test material present show normal uninhibited growth.

At test concentrations of 100 ppm (l/l0,000), 2-(N- 2-cyanoethyldithiocarbamylmethylene)-5-hydroxy- 4H-pyran-4-one and the Zn, Cu, Ni and Cd chelates thereof completely inhibit the growth of S. aureus, S. typhosa, Ps. aeruginosmandA. Niger.

The data show the toxicant of this invention is highly effective for controlling apple scab disease. No herbicidal effect upon the apple trees is observed even at the highest test concentration. In regard to phytotoxicity, at rates of 10 pounds per acre the toxicants of the Examples exhibit essentially no phytotoxic properties against a spectra of broadand narrow-leafed plants.

In another embodiment of the invention, 2-(N-2- cyanoethyldithiocarbamylmethylene)-5-hydroxy-4l-lpyran-4-one is applied to foliage of tomato plants. The procedure is essentially the same as described above for the apple tree tests except the treated and untreated plants are sprayed with a suspension of Phytophthora infestans the pathogen which causes the disease commonly called late blight. Comparisons are made with the commercial fungicide manganese ethylenebis dithiocarbamate (Maneb). The percent control based on untreated tomato plants at various concentrations is shown in the following table.

Percent Control of Late Blight Conc. ppm

The data show that the toxicant of this invention is more effective at low concentrations than the commercial fungicide. No phytotoxic effects due to the toxicant is observed. Similar tests with the chelates of this invention give substantially the same degree of control of apple scab and late blight.

Although the invention has been illustrated by typical examples, it is not limited thereto. Changes and modifications of the examples of the invention herein chosen for purposes of disclosure can be made which do not constitute departure from the spirit and scope of the invention. N v

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. The method of inhibiting the growth of fungi or bacteria which comprises applying to the habitat of the organism a fungicidal or bactericidal amount of Z-(N- Z-cyanoethyldithiocarbamylmethylene)--hydroxy- 4H-pyran-4-one or a metal chelate thereof.

2. The method of claim 1 in which 2-(N-2- cyanoethyldithiocarbamylmethylene)-5-hydroxy-4l-lpyran-4-one is employed.

3. The method of claim 1 in which a metal chelate of 2-(N-2-cyanoethyldithiocarbamylmethylene)-5 hydroxy-4H-pyran-4-one is employed.

4. The method of claim 3 in which the metal is selected from the group consisting of chromium, manganese, iron, cobalt, nickel, copper, zinc, cadmium, lead and mercury.

5. The method of claim 4 in which the metal is zinc.

6. The method of claim 4 in which the metal is copper.

7. The method of claim 4 in which the metal is nickel.

8. The method of claim 4 in which the metal is cadmium.

Phytophthora infestans. 

1. THE METHOD OF INHIBITING THE GROWTH OF FUNGI OR BACTERIA WHICH COMPRISES APPLYING TO THE HABITAT OF THE ORGANISM A FUNGICIDAL OR BACTERICIDAL AMOUNT OF 2-(N-2CYANOETHYLDITHIOCARBAMYLMETHYLENE)-5-HYDROXY-4H-PYRAN-4ONE OR A METAL CHELATE THEREOF.
 2. The method of claim 1 in which 2-(N-2-cyanoethyldithiocarbamylmethylene)-5-hydroxy-4H-pyran-4-one is employed.
 3. The method of claim 1 in which a metal chelate of 2-(N-2-cyanoethyldithiocarbamylmethylene)-5-hydroxy-4H-pyran-4-one is employed.
 4. The method of claim 3 in which the metal is selected from the group consisting of chromium, manganese, iron, cobalt, nickel, copper, zinc, cadmium, lead and mercury.
 5. The method of claim 4 in which the metal is zinc.
 6. The method of claim 4 in which the metal is copper.
 7. The method of claim 4 in which the metal is nickel.
 8. The method of claim 4 in which the metal is cadmium.
 9. The method of claim 2 in which the habitat is foliage.
 10. The method of claim 9 in which the organism is Venturia inaequalis.
 11. The method of claim 9 in which the organism is Phytophthora infestans. 